This invention relates to electric power distribution in general and more particularly to flexibly coupling movable consumers such as lifting equipment, transporting and conveyor machinery as well as material handling equipment to a stationary power network, using an electric multiconductor cable.
Flexible electric cables which are used for supplying power to movable consumers and which are wound and unwound continuously onto or off from a drum in the process, are subjected to considerable mechanical stresses. Sometimes, these stresses lead to corkscrew-like distortions of the cable. Basically, the design of such a power or control cable, which usually consists of conductors which are arranged about a core (dummy conductor) in one or two layers and a one or two layer jacket, which is optionally provided with an embedded braid, takes care of the occurring mechanical stresses (DE-AS No. 11 80 813, DE-AS No. 14 65 777, DE-OS No. 28 03 464). Even so, mechanical stresses which result in the above-mentioned distortions can occur due to torsion and tensile stresses placed on the conductors in conjunction with their mobility relative to each other as well as to the jacket.
Starting from an electric flexible multiconductor cable, the conductors of whch are stranded about a core in one or more layers, and are surrounded by a one layer or multilayer plastic or rubber jacket, it is an object of the present invention to modify the mechanical design of the cable so that the occurrence of corkscrew-like distortions is avoided.